Beta agonists in cattle debate beefs up

Producing food for the growing global population is one of the challenges for agriculture in the 21st century.

Non-hormone growth promotants known as beta agonists are a feed additive that help animals put on more muscle instead of fat, but they are not approved for use in Australian cattle.

There are, however, two approved beta agonists in America - zilpaterol hydrochloride and ractopamine hydrochloride.

Global animal health company MSD, which the Australian company Coopers is a subsidiary of, has an application with the Australian Pesticides and Veterinary Medicines Authority to register its zilpaterol hydrochloride product known as Zilmax in Australia.

Animal nutritionist Robert Lawrence says the appeal of beta-agonists are the production gains made possible by using the product.

"Beta agonists consistently and repeatedly provide improvements in daily gain and feed efficiency of 10 to 30 per cent and that translates to improvement in carcase weights of 5 to 15 kilograms."

Beta agonists are approved for use in the United States, Mexico, Canada and South Africa. However, there are 160 countries that don't allow the importation of beef which has been exposed to beta agonists.

As a result, the Cattle Council of Australia is against the use of the product within Australia for the time being.

The feedlot industry would be the main industry to use the product. However, the Australian Lot Feeders' Association does not have a position for or against the use of beta agonists.

ALFA president Don Mackay says the association plans to wait and collect more information on the topic before making a decision.

The manufacturer of zilpaterol hydrochloride has withdrawn the product from the market in America while concerns about animal welfare, such as the link between beta agonists and lameness, are investigated.

Animal welfare expert Temple Grandin is against the use of beta agonists in beef production for that reason.

"When beta agonists came into the market, I started seeing problems I'd never seen before."

"My biggest concern is that in some cattle there have been problems with the cattle showing up at the meatworks sore footed and stiff in the muscles and not wanting to walk, especially in very hot weather. And this is clearly not acceptable."

The impact beta agonists have on eating quality is also being looked at.

Meat and Livestock Australia's eating quality research and development manager Alex Ball says it's collecting a lot of information from around the world on beta agonists.

"Beta agonists do have an impact on tenderness, they can have an impact on marbling and ossification, but more importantly if we can quantify what those impacts are we can actually line up where they fit in terms of the production system."

Australian Pesticides and Veterinary Medicines Authority (APVMA) approved the use of ractopamine hydrochloride in pigs in 2003.